I just bought a 91 Loyale that seems to idle fine when first started, but as it warms up, the RPM's start dropping. Eventually, it stalls, and then it will only start and run if you keep the accelerator depressed. I've tried to check codes, but only get five rapid flashes repeated over and over (I must be doing something wrong). The car has a brand new MAF sensor installed (less than a month ago). I'm thinking the sinking idle is caused by a bad coolant temp sensor or maybe a problem with the IAC valve, but I just don't know. Wouldn't an IAC problem be more prevalent at cooler temperatures than warmer? If anyone has any ideas, I'd sure appreciate your thoughts. Thanks!

CTS - give it a test with your MM.

 

GD

First thought is a sticky EGR valve or clogged passage. Could be wrong though.

mine does that too. So as soon as she starts to stall I rev that sucker up and then its all good.

not mine, but ya.

 

http://videos.streetfire.net/search/subaru/7/81416196-2f9f-48a0-87a8-636cd5c4beb8.htm